How often are you planning on feeding it? Is it a baby or an adult? If an adult, what size is it?
I tend to feed my snakes 1-2 small items until they are a year old. If you do this too, feeding every 4 days when they are babies and moving to every 5 days, and then every 6 days as they get older, I would guess you would need approx. 100-120 pinky/fuzzy mice for it's first year.
Because mice produce about 8 per litter, about every 21-28 days, that means you would need about 15 litters of mice, however, I would say 20 litters just to be safe.
To get this number of litters in a relatively short period of time (3 months) you would need 4-5 females. I would use 5 females to be safe. You could use a bin of 1.5, but some say that is too many females for 1 male. If you want, you could use 2 bins, 1 that is 1.2 and 1 that is 1.3.
If you don't mind breeding mice for an extended period of time, you could just use 1.2 mice.
But remember, mice don't live that long (less than a year when you breed them a lot), so you would have to take that into account and make sure you replace the breeder mice every once in a while.
(NOTE: I suck at math, so hopefully all of these calculations are right.)